The 3GPP standard describes an Internet Protocol (IP) multimedia subsystem (IMS) that comprises the core network (CN) devices that provide IP multimedia services, including audio, video, text, chat and the like, and combinations thereof, delivered over the Internet and/or the public switched telephone network. Conventional IP multimedia subsystems generally comprise an IP switch and a single server. As network loading increases, more processors may be added to the server to cope with the increased throughput requirements.
However, at some point, adding more processors becomes inadequate due to limitations in the capacity of the server. For example, the bandwidth of the server may limit the usefulness of this approach. In a number of systems, it is not possible to add more processors. At that point, faster and more powerful processors must be added, which also is a limited approach.
Also, the conventional architecture of an IP switch and a single server is limited by a single point of failure. If the server fails, then all service is lost. The prior art IP multimedia subsystems use the IP switch to detect when a node has failed. The conventional IP multimedia subsystems do not detect when a server has failed.
Therefore, there is a need in the art for an improved IP multimedia subsystem that is capable of providing scalable service to cope with increased traffic requirements. In particular, there is a need for an IP multimedia subsystem that does not contain a single point of failure.